JPH04164603A - Manufacture of curved laminated plate - Google Patents

Abstract

PURPOSE:To obtain the above plate of a sector or an arc shape by a method in which after the stock of a rectangular lumber has been kept in high moisture content by moisture-containing treatment and has been heated, the stock is pressed and is bent, and then the stocks are assembled into a final completed shape by combination and are dried, and further after the stocks have been successively bonded and laminated from a small diameter-stock to a large diameter stock, they are finish-worked. CONSTITUTION:The stock in which dried wood is formed into a rectangular lumber is kept in high moisture-content of at least 60%. The stock with high moisture content is heated to 120-150 deg.C. The stock having high moisture content and high temperature- treated are pressed in the state of two - four stocks being superimposed and are worked by bending. The stocks are successively laminated from the stock of small curvature-radius to that of large curvature radius, and are formed into a semicircle or a sector, and then they are firmly bound by a belt and are dried until their moisture contents reach about 10%. While each one layer is coated with an adhesive from the small diameter stock, the bonding operation is repeated. The front surface and the side surface of the laminated plate in which its bonding is finished and its shape is completed are shaved smoothly or are worked by coating, whereby the laminated plate is made an article.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a special laminated board. To describe this in detail, a long square board with a thickness of approximately 1.5 cm to 3 cm and a width of several cm is curved. This is an excellent manufacturing method in which the pieces are laminated and glued together to form the whole into a fan-shaped or arc-shaped laminated board.The laminated board obtained by this method has a beautiful appearance, so it has high utility value as a high-grade furniture board material. It's expensive.

[Conventional technology]

What is conventionally known as laminated board is made by gluing together many short pieces of various types of wood and pressing them together to form a structural material, that is, a piece of wood made from a large tree in terms of thickness and length. They are made of comparable material, and some have a gentle arch-like curvature. However, in the field of laminated boards used for furniture, etc., curved boards are not seen. The reason is that the radius of curvature is small and manufacturing is extremely difficult.

Conventionally, many proposals have been made regarding the curvature of wood.

For example, for gentle curves,
No. 1, and regarding deep curves, there is Tokukoho No. 1-39881, etc. However, in the present invention, since the radius of the curve is small and the curved materials are laminated and bonded to form a plate-like body, care is taken to prevent the curved materials from peeling off from each other.
Strict properties are required, and in this respect, the previously proposed methods for bending wood are found to be inadequate.

[Problem to be solved by the invention]

In the present invention, the wood is made into elongated rectangular pieces, which are made long and each piece has a different radius of curvature or is laminated one after another.
If the bending process is uneven, adjacent curved materials will not join perfectly, creating gaps or warping, which can easily cause quality problems. Therefore, the bending process becomes more severe than before, and the technique becomes difficult. Furthermore, considering the cost aspect, it was recognized that conventional bending techniques were insufficient and that improvements were needed in terms of adhesive processing as well.

[Means for solving problems]

The present invention was obtained as a result of various tests and researches for the purpose of machine-producing curved laminated boards as members for the above-mentioned construction work to reduce costs and ensure stable quality. The technical philosophy is as follows.

The manufacturing method of the present invention consists of five steps, and to explain them step by step, the first step is to mainly perform a water treatment on the material. The wood (material) is treated with moisture to have a moisture content of 60% or more, and the material that has a moisture content of 60% or more is further treated with water.
It consists of a heat treatment of heating to a high temperature of 20°C or higher. Second
The process is mainly a bending process in which the heated high water content material is pressed against curved surfaces with various radii of curvature for a certain period of time, using a Thonet. In the third step, the curved materials with different radii of curvature obtained in this way are laminated in order from the one with the smallest radius of curvature to the one with the largest curvature radius to form a fan shape, semicircle, or arc shape, and then the whole is wrapped with a belt etc. While tightly tied, the moisture content of the material is normal10
This is a drying process that mainly involves natural drying until the

The fourth step is the adhesion step, in which the adjacent contact surfaces are sequentially cut from the smallest radius of curvature to the largest one using a curved cutting machine to obtain a smooth and accurate radius of curvature, and each piece thus finished has a uniformity. An adhesive is applied to the surface that will come into contact with the curved material, and the curved material is glued one piece at a time from small to large to complete the desired shape. The fifth step is the finishing step, in which the surfaces of the fan-shaped and other shapes of the laminated plates mentioned above are planed and polished to make them smooth, and the side surfaces are also finished for shaping. It is a process.

This will be explained more specifically and the characteristics of the present invention will be described.

In the first step, the material with dimensions of, for example, 25 mm thick, 40 mm wide, and 400 mm long is placed in a vacuum pot, and after the air inside the wood material is removed, water is poured into the pot. The material is sprayed to impregnate the inside with water, and the water that soaks the material is poured into the pot, and then this water is brought to a boil. By placing the material in this boiling water for 20 hours, its moisture content is brought to 60% to 90%. Thus, the highly water-containing material is heated to a high temperature of 120'C or higher while still in a highly water-containing state. In this case, wrap the material in plastic wrap to prevent the moisture content from escaping and to quickly reach high temperatures.
It is preferable to use a microwave oven (microwave heater) or the like.

Next, in the second step, the high water content high temperature material is quickly fitted into a Thonet, both ends of the material are fixed, and in this state the material is pressed and bent. Specifically, the material is placed on the concave curved surface (female type) of a bending table, which is a jig having a curved surface with a constant radius of curvature, which is attached to a press machine, and the material is placed on the convex curved surface (female type) from above.
A curved material having a predetermined curvature can be obtained by pressing the material using a male mold and leaving it in this state for about 12 hours. In this process, in addition to placing the materials directly on the jig and pressing them as described above, two to four adjacent materials located on top of this material are stacked on top of one material in a laminated state. By pressing, it is possible to bend 2 to 4 pieces with a -degree press. This is due to the excellent plasticity of the material used in the present invention. Note that the radius of curvature changes in size based on the thickness of the material (
Figure 1). If the thickness of the materials differs, the jig must also correspond to this.

The third step is drying, and as mentioned above, the materials are assembled into the final completed shape, and this is tightly tied with a belt and air-dried or heated to a moisture content of approximately 10.
Dry to %.

This drying method is slow in drying, but from the viewpoint of improving the finish of the product, various experiments have shown that this method is the best.
It was recognized that the product was superior in terms of durability, that is, adhesion, and no gaps or distortions.

Regarding the adhesion in the fourth step, it is important to cut the surfaces of the stacked curved materials that are in contact with adjacent ones with a curved surface cutting machine so that the radius of curvature is accurate. After this preparation, an adhesive is applied, and the pieces are laminated sequentially from small diameter pieces to large diameter pieces to form a predetermined shape. Since the fifth step is a finishing step, the above-mentioned points are the main ones, and other processing, such as painting and polishing, can be carried out freely.

[For production]

The present invention consists of the above-mentioned steps, and the operation will be explained below.In the first step, 60% of the material is
By heating the highly hydrated material to a high temperature of 120°C to 150°C, the wood material can be bent accurately in accordance with the purpose of the present invention. It becomes possible to process it. Since the object of the present invention is a curved laminated board, the accuracy of the radius of curvature of each curved material constituting the board is strictly required. Therefore, the value of the product will be lost, so 5←. The second step is press processing using a jig.In the present invention, since the material is subjected to high water content and high temperature treatment in the first step, the material is not pressed in one piece, but two to four pieces are stacked. It is possible to bend 2 to 4 pieces of material at one time by pressing the material in a bent state, and the bending process is easy. In the third step, the thus bent materials are laminated in order from the smallest to the largest radius of curvature, formed into a semicircle or fan shape, and then tied tightly with a belt and dried in this state. Therefore, the laminated state is maintained correctly even after drying.

Drying is continued until the moisture content is approximately 10%.

Natural drying or various artificial drying means can be employed. In the fourth process of adhesion, it is necessary to smooth the contact surfaces between adjacent objects, and also to repair some twists and distortions that have occurred. Once the materials are prepared, glue is applied to each layer starting from the smallest diameter, and the adhesive process is repeated to complete the entire piece.

In the finishing process of the fifth step, after the bonding is completed and the shape of the laminated board is completed, the surface and side surfaces of the board are ground flat or painted, and the board is commercialized.

〔Example〕

Next, examples will be described with reference to the drawings. Beech wood width 4
After placing an appropriate number of square timbers (materials) with a thickness of 25 mm, a thickness of 25 mm, and a length of 400 mm into a vacuum cooker and once reducing the pressure, water is sprayed into the cooker to sufficiently impregnate the material with moisture. Furthermore, by boiling this material in a pot for about 1 hour, the moisture content of the material is about 75%, then quickly wrap it in plastic wrap (packaging material) and quickly microwave it at 140℃.
Heat to.

Two of these high water content, high temperature materials a and b are each used as Thonet 1.
and place it on the female mold P2 of the press device P (Fig. 2)
Next, the male die P1 of the press device is lowered to apply pressure to the materials a and b to bend them. Since the material has a moisture content higher than that of raw wood, bending is easy, and there is almost no cracking or distortion of the material, resulting in highly accurate bending. Pressing time is about 12 hours. Similarly, materials with different radii are made by replacing the male and female dies of the press with jigs with different radii of curvature and pressing the materials.

The necessary curved materials obtained in this way from small diameters to large diameters were laminated in order from small diameter ones to large diameter ones, assembled into the shape shown in Figure 1, and tied tightly with a belt.
Air dry for a week until the moisture content of the material is approximately 10%. As a means for faster drying, artificial drying means such as heating or heating under reduced pressure may be partially used. However, since the moisture content of the material is extremely high, it takes the number of days mentioned above to dry it to about 10%, and rapid drying causes distortion and twisting of the material, resulting in many defective products. That's why I don't like it.

In this way, curved pieces m, which are curved dry members having different radii of curvature, are obtained.

Next, the curved pieces m are bonded in a layered manner, but first the bonding surfaces are cut smooth. That is, by using a curved surface cutting machine,
Smooth the surfaces that contact the top and bottom to get the correct radius, then apply adhesive (for example, lead acid vinyl resin emulsion adhesive) to only one of the contact surfaces of the vertically adjacent curved pieces m and m, and then are joined, fixed with a jig, left for about 5 to 6 hours to ensure adhesion, then the jig is removed and the next piece m is bonded in the same way. By repeating this process, the laminated board shown in Figure 1 was completed.

In the final finishing step, the surface of the plate assembly completed through the above-mentioned process is smoothed, and if necessary, both end faces are finished smooth. In this way, a fan-shaped laminated board with curved wood grains and beautiful appearance as shown in Figure 1 was obtained.

Note that three to four fan-shaped laminated boards thus obtained can be joined together to make a circular top plate, or can be used as a corner material of a frame.

〔effect〕

Since the present invention includes the above-mentioned manufacturing method, it is possible to produce a laminated board made of laminated curved pieces m, which have never been seen in furniture, etc., with good quality and yield, and to significantly reduce production costs. This makes it possible to provide a novel construction member.

[Brief explanation of drawings]

FIG. 1 shows an example of a laminated wood board obtained by the method of the present invention, in which (a) is a plan view and (b) is a side view. FIG. 2 is an explanatory diagram when two materials are curved using a press machine, and FIG. 3 is an explanatory diagram showing the curved state. Code explanation: a, b...Material, m...Curved piece, P...Press machine, Pl...Male type,
P2... Female type, 1... Thonet. $IWJ

Claims (2)

[Claims] (1) Put dried wood into a square shape into a vacuum cooker.
The material is hydrated by spraying water under reduced pressure, then boiled to have a moisture content of 65% or more, wrapped in a packaging material, and heated in a microwave heater at 120°C to 100°C.
The second step consists of a first step of heating the material to 40° C., and a pressing step of bending the material heated to contain water from a small radius of curvature to a large radius of curvature using the thickness of the square material as a unit.
A state where a large number of curved materials with large and small radii of curvature obtained in this way are laminated in order from small diameter to large diameter and assembled into a fan shape or semicircle, which is tightly bound with a belt. a third step of drying the curved pieces (m), a fourth step of gluing the dried curved pieces (m) in order from small diameter to large diameter, and a surface and side surface of the laminated board thus formed. A method for manufacturing a curved laminated board, characterized by comprising a fifth step of cutting the board smoothly and applying finishing processes such as painting and polishing. (2) The method for manufacturing a curved laminated board according to claim 1, wherein the bending process is performed in a state in which two to four materials are laminated in the pressing process.